This invention relates to a method and apparatus for an internal combustion engine which can detect when a cylinder of the engine is misfiring and cut off the supply of fuel to the misfiring cylinder while allowing the remaining cylinders to continue to operate.
When a cylinder of an internal combustion engine misfires, uncombusted fuel and air are discharged from the engine. When the uncombusted fuel and air reach the catalytic converter for the engine, a sudden chemical reaction takes place, causing a great increase in the temperature of the catalytic converter. In this state, the catalytic converter can not function properly, and harmful exhaust gases are discharged into the atmosphere. The large increase in temperature also produces damage or degradation of the catalytic converter and shortens its life span. Furthermore, when an automobile is stationary, if dead grass or other combustible material should contact the catalytic converter when it is at an abnormally high temperature due to misfiring, there is the possibility of a fire starting.